Hozelock Cyprio manufactures BioForce UVC Pond Filters designed to keep your pond fresh by treating the water with a foam-sleeve filter and an ultraviolet bulb. These filter parts are the same for all, but come in different sizes. Verify the size and model number of your filter when ordering parts
How do I know if my BioForce is Pre-2002 or Post-2002?
The only BioForce filters that it really makes a difference are 500 and 1000. If the filter media inside both units is one piece, it is pre 2002. If the filter pads are 2 pieces for the 500 and 3 pieces for 1000, then it is post 2002. The Bio Force 2000 has always had 3 pieces to complete it's filter pads.